It is common for automatic car wash systems of the conveyor type to employ a means for properly positioning vehicles at a point of entry. Conveyor systems may use tire guides not only to force a vehicle into a proper entry position but also to guide the vehicle through the various stations from entry to exit.
For non-conveyor washers such as “touchless automatic” systems using pressurized streams of sprayed fluids to wash and rinse vehicles, it is known to use various devices including off-center treadles to determine when a vehicle is in a proper position to be washed. Treadles, by their very nature, may position the left or driver's side of a vehicle, but do not purport to center a vehicle in a bay.